Antioxidant, Anti-inflammatory, and Antibacterial Activities of Actinobacteria Isolated from Marine Sediment

Secondary metabolites associated with bacteria possess various biological activities such as antioxidant and antibacterial effects. Here, we isolated approximately 90 strains from marine sediments and obtained 7% Actinobacteria among them based on biological activity. The genus Streptomyces is considered as promising source of bioactive secondary metabolites. Several Streptomyces strains and other strains showed antioxidant, antiinflammatory, and antibacterial activities. Most strains (those selected for biological activity in this study) showed antibacterial effects against Staphylococcus aureus KCTC1927 and Salmonella typhimurium KCTC1925. Extracts of Streptomyces sp. SCS525 and Planomicrobium sp. SCS1153 showed strong antioxidant activity in DPPH and ABTS assays. Streptomyces sp. SCS525 and SCS538, Arthrobacter sp. SCS553, Microbacterium sp. SCS1115, and Planomicrobium sp. SCS1153 showed anti-inflammatory effects in NO and PGE₂ production experiments. Thus, Actinobacteria isolated from marine sediments possess promising biological activities. However, fractionation and further characterization of active compounds from these strains are needed for their optimum utilization.